Tutorial :How does jQuery affect CSS structure

Question:

Just re-entering heavy duty js and CSS world after a couple years working only in Flash and coming up to speed on jQuery. I'm designing some CSS/DIV-based layouts and will be depending on jQuery and AJAX for interactions.

As regards the CSS coding conventions and structure, how can I design SS to best take advantage of jQuery?

What CSS concepts should I be mastering if I want my jQuery design work to dovetail with the CSS work?